Color control encapsulation layer and display apparatus including the same

ABSTRACT

A display apparatus includes an organic light-emitting device (“OLED”) substrate which generates and emits a first light, and an encapsulation layer to which the emitted first light from the OLED substrate is incident and from which a second light is emitted. The encapsulation layer includes an inorganic material layer and an organic material layer alternately stacked with each other. The organic material layer includes a plurality of color control elements which color-convert the emitted first light incident to the encapsulation layer. The plurality of color control elements may include a first and second color control element including a first and second quantum dot with which a color of the emitted first light incident to the encapsulation layer is converted to a first and second color, respectively.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 16/855,294 filed Apr. 22, 2020 and issued as U.S. Pat. No.11,271,050 on Mar. 8, 2022, which is a continuation application of U.S.application Ser. No. 16/152,905 filed Oct. 5, 2018 and issued as U.S.Pat. No. 10,686,019 on Jun. 16, 2020, which claims priority to KoreanPatent Application No. 10-2017-0155807, filed on Nov. 21, 2017, and allthe benefits accruing therefrom under 35 U.S.C. § 119, the disclosure ofwhich is incorporated herein in its entirety by reference.

BACKGROUND 1. Field

Embodiments set forth herein relate to display apparatuses.

2. Description of the Related Art

Organic light-emitting devices (“OLED”) are self-light-emitting typedevices having a wide viewing angle, excellent contrast, high responsespeed, superior characteristics in terms of a driving voltage,luminance, etc. and being capable of generating multiple colors.

An OLED may include an anode, a cathode, and an emission layer (anorganic material-including emission layer) interposed between the anodeand the cathode. A hole transport region may be located between theanode and the emission layer. An electron transport region may belocated between the emission layer and the cathode. Holes injected fromthe anode may move to the emission layer via the hole transport region.Electrons injected from the cathode may move to the emission layer viathe electron transport region. Carriers such as holes and electrons mayrecombine in the emission layer to produce excitons. Light may begenerated as the excitons change from an excited state to a groundstate.

Hybrid technologies of applying quantum-dot materials to organiclight-emitting device (“OLED”) type displays have drawn attention.Quantum dots are nanometer-sized semiconductor crystals. An energy gapof quantum dots may be controlled according to a size and shape of thequantum dots. When a semiconductor material is reduced to a size ofnanometers like the quantum dot, unique optical characteristics may begenerated due to a quantum mechanics phenomenon. Particularly, thequantum dots have high luminous efficiency and a narrow full width athalf maximum (“FWHM”) in a visible-light region, and thus are expectedto be a next-generation display material.

SUMMARY

Provided are display apparatuses which have excellent encapsulationproperties with regard to an external environment and which may berelatively easily manufactured.

Provided are display apparatuses capable of suppressing color blurringor color mixing.

Provided are display apparatuses in which color conversion elements areapplied in an encapsulation layer structure.

Provided are methods of manufacturing the display apparatuses.

Additional features will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an embodiment, a display apparatus includes an organiclight-emitting device (“OLED”) substrate which generates and emits afirst light, and an encapsulation layer to which the emitted first lightfrom the organic light-emitting device substrate is incident and fromwhich a second light is emitted, the encapsulation layer including aninorganic material layer and an organic material layer alternatelystacked with each other. The organic material layer of the encapsulationlayer includes a plurality of color control elements which color-convertthe emitted first light incident to the encapsulation layer. Theplurality of color control elements include a first color controlelement including a first quantum dot with which a color of the emittedfirst light incident to the encapsulation layer is converted to a firstcolor, and a second color control element including a second quantum dotwith which the color of the emitted first light incident to theencapsulation layer is converted to a second color.

The encapsulation layer may further include a first inorganic materiallayer, a second inorganic material layer and the organic material layerincluding the plurality of color control elements between the first andsecond inorganic material layers.

The first quantum dot of the first color control element may convert thecolor of the emitted first light incident to the encapsulation layerinto red, and the second quantum dot of the second color control elementmay convert the color of the emitted first light incident to theencapsulation layer into green.

The organic material layer may further include a light-scatteringelement adjacent along the organic light-emitting device substrate tothe plurality of color control elements. The light-scattering elementmay maintain the color of the emitted first light incident to theencapsulation layer.

The plurality of color control elements may further include a thirdcolor control element adjacent along the organic light-emitting devicesubstrate to the first and second color control elements, the thirdcolor control element, the third color control element including a thirdquantum dot with which the color of the emitted first light incident tothe encapsulation layer is converted to a third color.

The display apparatus may further include a color filter layer to whichthe emitted second light from the encapsulation layer is incident.

The display apparatus may further include a plurality of sub-pixelregions at which color light is emitted to display an image. The colorfilter layer may include respectively corresponding to the plurality ofsub-pixel regions: a first color filter which corresponds to the firstcolor control element of the encapsulation layer, a second color filterwhich corresponds to the second color control element of theencapsulation layer, and a third color filter.

Within the color filter layer to which the emitted second light from theencapsulation layer is incident, the first color filter may be a firstcut-off filter which selectively transmits light in a red lightwavelength region. The second color filter may be a second cut-offfilter which selectively transmits light in a green light wavelengthregion. The third color filter may be a third cut-off filter whichselectively transmits light in a blue light wavelength region.

Within the color filter layer to which the emitted second light from theencapsulation layer is incident, the first color filter may be anabsorption type red color filter. The second color filter may be anabsorption-type green color filter. The third color filter may be anabsorption-type blue color filter.

The OLED substrate may include a first electrode, a second electrode,and an organic emission layer between the first and second electrodes.The first and second electrodes may be electrically separated from theinorganic material layer of the encapsulation layer.

The organic material layer of the encapsulation layer may include aphotocurable organic material and a light-scattering agent.

The organic material layer of the encapsulation layer may have athickness of about 10 nanometers (nm) to about 10000 nm.

The inorganic material layer of the encapsulation layer may include anyone of a metal nitride, a metal oxide, a metal oxynitride, a metalcarbide and a combination thereof.

The inorganic material layer of the encapsulation layer may be aninsulating layer or a semiconductor layer.

The inorganic material layer of the encapsulation layer may have athickness of about 10 nm to about 5000 nm.

Within the encapsulation layer, the first and second inorganic materiallayers may each extend along the organic material layer to dispose endsof the first and second inorganic material layers spaced apart fromouter sides of the organic material layer, the first and secondinorganic material layers being bonded to each other at the endsthereof.

The OLED substrate may be a blue OLED substrate which emits blue firstlight, a white OLED substrate which emits white first light, or a cyanOLED substrate which emits cyan first light.

The display apparatus may further include a thin-film transistor (“TFT”)array substrate connected to the OLED substrate to drive the substrate.The TFT array substrate may include a plurality of TFTs connected topixel regions of the OLED substrate to drive the pixel regions of thesubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other features will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view of a display apparatus according to anembodiment;

FIG. 2 is a cross-sectional view of a display apparatus according toanother embodiment;

FIG. 3 is a cross-sectional view of a display apparatus according toanother embodiment;

FIG. 4 is a cross-sectional view of a display apparatus according toanother embodiment;

FIG. 5 is a cross-sectional view of a display apparatus according toanother embodiment;

FIG. 6 is a cross-sectional view of a display apparatus according toanother embodiment;

FIG. 7 is a detailed cross-sectional view of a structure of a displayapparatus, according to an embodiment;

FIG. 8 is a cross-sectional view of a structure of an encapsulationlayer applicable to a display apparatus, according to anotherembodiment;

FIG. 9 is a cross-sectional view of a display apparatus according toanother embodiment;

FIG. 10 is a cross-sectional view of a display apparatus according toanother embodiment;

FIG. 11 is a graph showing an electroluminescence (“EL”) spectrum of ablue organic light-emitting display device (“OLED”) substrate applicableto a display apparatus according to an embodiment;

FIG. 12 is a graph showing photoluminescence (“PL”) quantum yield (%)according to wavelengths of a color conversion element including a redquantum dot (“QD”) and a color conversion element including a green QD,applicable to a display apparatus according to an embodiment;

FIG. 13 is a graph showing a variation in transmittance (%) versuswavelengths of a color conversion element including a red QD and a colorconversion element including a green QD, applicable to a displayapparatus according to an embodiment;

FIG. 14 is a graph showing a variation in transmittance (%) versuswavelength of an absorption-type color filter applicable to a displayapparatus according to an embodiment;

FIG. 15 is a graph showing a variation in transmittance (%) versuswavelength of a cut-off-type color filter applicable to a displayapparatus according to an embodiment;

FIG. 16 is a graph showing a spectral radiance difference between when alight-scattering agent is applied to blue light and when thelight-scattering agent is not applied to blue light; and

FIG. 17 is a graph showing an emission spectrum according to awavelength of a display apparatus according to an embodiment.

DETAILED DESCRIPTION

Various example embodiments will now be described more fully withreference to the accompanying drawings in which example embodiments areshown.

It will be understood that when an element is referred to as beingrelated to another element such as being “connected” or “coupled” toanother element, it can be directly connected or coupled to the otherelement or intervening elements may be present. In contrast, when anelement is referred to as being related to another element such as being“directly connected” or “directly coupled” to another element, there areno intervening elements present.

As used herein the term “and/or” includes any and all combinations ofone or more of the associated listed items. Expressions such as “atleast one of,” when preceding a list of elements, modify the entire listof elements and do not modify the individual elements of the list. “Atleast one” is not to be construed as limiting “a” or “an.” “Or” means“and/or.”

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of example embodiments.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprise” and/or “comprising,” when used in this specification, specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of exampleembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, example embodiments should not be construed aslimited to the particular shapes of regions illustrated herein but areto include deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the figures are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to limit the scope ofexample embodiments.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10% or 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, such as those defined incommonly-used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Hereinafter, display apparatuses according to embodiments will bedescribed in detail with reference to the accompanying drawings. In thedrawings, a width and thickness of each layer or region may beexaggerated for clarity and convenience of explanation. Throughout thedetailed description, same reference numerals represent same elements.

FIG. 1 is a cross-sectional view of a display apparatus according to anembodiment.

Referring to FIG. 1 , an organic light-emitting device (“OLED”)substrate 100A may be provided. A multi-layer encapsulation layer 200Amay be located on the OLED substrate 100A.

The display apparatus and elements thereof may be disposed along firstand second directions which cross each other. In FIG. 1 , for example,the horizontal direction may represent the first and/or the seconddirection. A thickness of the display apparatus and element thereof istaken along a third direction which crosses each of the first and seconddirections. In FIG. 1 , for example, the vertical direction representsthe thickness (e.g., third) direction. A top or front of the displayapparatus may be defined at a side thereof at which light is emitted.

The OLED substrate 100A may be a light-source OLED. The OLED substrate100A may include a first electrode, a second electrode, and an organicemission layer between the first and second electrodes. The firstelectrode may be an anode and the second electrode may be a cathode, orvice versa. The OLED substrate 100A may further include an electrontransport layer and a hole transport layer, and may additionally includea hole injection layer and an electron injection layer.

The OLED substrate 100A may be, for example, a blue-OLED substrateemitting blue light, a white-OLED substrate emitting white light, or acyan-OLED substrate emitting cyan light. However, colors of lightemitted from the OLED substrate 100A are not limited thereto and arevariable. In the following description with reference to FIG. 1 , theOLED substrate 100A is a blue-OLED substrate but is merely an example.In an embodiment of manufacturing the OLED substrate 100A, the OLEDsubstrate 100A may be formed using an open mask process such that theOLED substrate 100A has the same structure (a uniform structure) at alllocations when viewed from a top view (e.g., along the thicknessdirection from the top or front), but the open mask process may not beused according to circumstances.

The encapsulation layer 200A may have a structure in which an inorganicmaterial layer and an organic material layer are alternately stackedwith each other at least once. At least one organic material layer ofthe encapsulation layer 200A may include color control elementsincluding quantum dots (“QDs”). When one inorganic material layer andone organic material layer together form one encapsulation unit, ‘n’number of encapsulation units may be provided. Here, ‘n’ may be greaterthan or equal to 1.

Referring to FIG. 1 , for example, the encapsulation layer 200A may havea structure in which a first inorganic material layer 210, an organicmaterial layer 220 and a second inorganic material layer 230 aresequentially stacked along the thickness direction of the displayapparatus.

The organic material layer 220 may include a plurality of color controlelements 20 a and 20 b to control a color of light generated by the OLEDsubstrate 100A. The color control elements 20 a and 20 b may include afirst color control element 20 a including a first QD to realize a firstcolor, and a second color control element 20 b including a second QD torealize a second color. The second color may be different from the firstcolor.

The organic material layer 220 may further include a light-scatteringelement 21 c located at a side (lateral side) of the color controlelements 20 a and 20 b, such as along the first and/or second direction.The light-scattering element 21 c may be a region that does not includea QD, e.g., a non-QD-including region. That is, the light-scatteringelement 21 c maintains the color of the light emitted from the OLEDsubstrate 100A and incident to the encapsulation layer 200A. The organicmaterial layer 220 including the color control elements 20 a and 20 b towhich QDs are applied may be sandwiched between the two inorganicmaterial layers 210 and 230. Thus, a lowermost layer and an uppermostlayer of the encapsulation layer 200A may be respectively the inorganicmaterial layers 210 and 230. The light-scattering element 21 c may beprovided in plurality within the display apparatus. The color controlelements 20 a and 20 b and the light-scattering element 21 c within asame organic material layer 220 are disposed at substantially a samedistance as each other from the OLED substrate 100A along the thicknessdirection of the display apparatus.

The encapsulation layer 200A may encapsulate the color control elements20 a and 20 b therein while encapsulating the OLED substrate 100Athereunder. Furthermore, the encapsulation layer 200A may have a colorcontrol function since the color control elements 20 a and 20 b areincluded therein.

The first color control element 20 a may be a red-QD-including layer andmay convert a color of light generated by the OLED substrate 100A intolight having a red (R) color. The second color control element 20 b maybe a green-QD-including layer and may convert a color of light generatedby the OLED substrate 100A into light having a green (G) color. Thus,the first color control element 20 a may be referred to as a first colorconverter (or color conversion element), and the second color controlelement 20 b may be referred to as a second color conversion element. Inan embodiment of manufacturing the encapsulation layer 200A, the colorconversion elements may be formed by combining a photocurable organicmaterial, certain QDs and a light-scattering agent. The photocurableorganic material may include, for example, a resin material such as aphotoresist (“PR”) material.

The light-scattering element 21 c may scatter light without changing thecolor of light generated by the OLED substrate 100A. Since each of thefirst and second color control elements 20 a and 20 b may include alight-scattering agent, the light-scattering element 21 c may beprovided at a side of the first and second color control elements 20 aand 20 b to achieve color balance. The light-scattering element 21 c mayinclude a photocurable organic material and a light-scattering agent.Here, the photocurable organic material may include a photoresist (“PR”)material, and the light-scattering agent may include, for example,titanium oxide (TiO₂) or the like but embodiments are not limitedthereto.

The first QD included in the first color control element 20 a may be ared QD. The second QD included in the second color control element 20 bmay be a green QD. Each of the QDs may be a semiconductor particlehaving a nanometer (nm) sized spherical shape or a shape similar theretoand having a size (e.g., diameter) of about several to several tens ofnanometers.

The QD may have a monolithic structure or a core-shell structure. Whenthe QD has the core-shell structure, the QD may have a single-shellstructure of a multi-shell structure. In an embodiment, for example, theQD may consist of a core portion (e.g., center portion) including orformed of a first semiconductor and a skin portion (e.g., shell portion)including or formed of a second semiconductor. Here, a material of thecore portion (e.g., center portion) may be cadmium selenide (CdSe),cadmium telluride (CdTe), cadmium sulfide (CdS), or the like. A materialof the skin portion (e.g., shell portion) may be zinc sulfide (ZnS) orthe like. Alternatively, a material of the skin portion (e.g., shellportion) may be a cadmium-free based QD. That is, various materials thatdo not include cadmium (Cd) may be applied to the QD. However, theabove-described materials are merely examples and other variousmaterials may be applied to the QD. In embodiments, for example, the QDmay include at least one among a Group II-VI-based semiconductor, aGroup III-V-based semiconductor, a Group IV-VI-based semiconductor, anda Group IV-based semiconductor.

The QD has a relatively very small size and may thus exhibit the quantumconfinement effect. When a size of a particle is relatively very small,electrons in the particle form a discontinuous energy state due to theouter walls of the particle. As the size of an inner space of theparticle decreases, an energy state of the electrons relativelyincreases and energy band intervals increases. This effect refers to thequantum confinement effect. Due to the quantum confinement effect, whenlight such as an ultraviolet ray or visible light is incident on the QD,light of various wavelength ranges may be generated.

A wavelength of light generated by the QD may be determined by a size,material and/or structure of the QD. In detail, when light of awavelength having energy higher than an energy band interval is incidenton the QD, the QD absorbs the energy of the light and is thus excited,emits light of a specific wavelength, and changes to a ground state. Inthis case, when the size of the QD (or the core portion of the QD) isrelatively small, light of a relatively short wavelength, e.g., blue orgreen light, may be generated. When the size of the QD (or the coreportion of the QD) is relatively large, light of a relatively longwavelength, e.g., red light, may be generated. Accordingly, light ofvarious colors may be achieved according to the size of the QD (or thecore portion of the QD).

A QD particle emitting green light may be referred to as a green-lightQD particle (e.g., a green QD particle). A QD particle emitting redlight may be referred to as a red-light QD particle (e.g., a red QDparticle). In an embodiment, for example, the green-light QD particle(or core portion) may be a particle having a width (e.g., diameter) ofabout 2 nm to about 3 nm, and the red-light QD particle (or coreportion) may be a particle having a width (e.g., diameter) of about 5 nmto about 6 nm. A wavelength of emitted light may be controlled accordingto a material and structure of the QD, as well as the size (e.g.,diameter) of the QD.

A color filter layer 300A may be further provided on the encapsulationlayer 200A. An upper surface of the color filter layer 300A may define alight emitting surface of the display apparatus without being limitedthereto. The color filter layer 300A may include first, second and thirdcolor filters 30 a, 30 b and 30 c respectively corresponding to aplurality of sub-pixel regions of the display apparatus at which colorlight is emitted such as to display an image. The first color filter 30a may correspond to the first color control element 20 a. The secondcolor filter 30 b may correspond to the second color control element 20b. The third color filter 30 c may correspond to the light-scatteringelement 21 c.

The first, second and third color filters 30 a, 30 b and 30 c may beabsorption type color filters including pigment or dye. The first colorfilter 30 a may be an absorption type red-color filter (C/F). The secondcolor filter 30 b may be an absorption type green-color filter (C/F).The third color filter 30 c may be an absorption type blue-color filter(C/F). The red-color filter 30 a may selectively transmit light of a redwavelength region and absorb light of the other wavelength regions. Thegreen-color filter 30 b may selectively transmit light of a greenwavelength region and absorb light of the other wavelength regions. Theblue-color filter 30 c may selectively transmit light of a bluewavelength region and absorb light of the other wavelength regions. Bysuch transmitting and absorbing described above, the first color filter30 a may filter out undesired light among light incident thereto afterpassing through the first color control element 20 a. Similarly, thesecond color filter 30 b may filter out undesired light among lightincident thereto after passing through the second color control element20 b and the third color filter 30 c may filter out undesired lightamong light incident thereto after passing through the light-scatteringelement 21 c. Full RGB colors may be achieved using the color controlelements 20 a and 20 b and the color filter layer 300A. Here, theabove-described order or method of the arrangement of RGB sub-pixels aremerely an example and may be changed variously.

In the color filter layer 300A, partitions 35 may be respectivelyprovided between the first color filter 30 a and the second color filter30 b and between the second color filter 30 b and the third color filter30 c. The partitions 35 may be a type of black matrices. In anembodiment of manufacturing the color filter layer 300A, after thepartitions 35 are formed, the first to third color filters 30 a, 30 b,and 30 c may be formed in regions defined by the partitions 35. Thepartitions 35 may reduce or effectively prevent different colors oflight emitted at pixels or sub-pixels from being mixed with each other.

The inorganic material layers 210 and 230 of the encapsulation layer200A may include a metal nitride, a metal oxide, a metal oxynitride, ametal carbide, or a combination thereof. In an embodiment, for example,the inorganic material layers 210 and 230 may include a silicon nitride,an aluminum nitride, a zirconium nitride, a titanium nitride, a hafniumnitride, a tantalum nitride, a silicon oxide, an aluminum oxide, atitanium oxide, a tin oxide, a cerium oxide, a silicon oxynitride, or acombination thereof. The inorganic material layers 210 and 230 may beinsulating layers or semiconductor layers. The inorganic material layers210 and 230 may each have a thickness of about 10 nm to about 5000 nm,for example, a thickness of about 50 nm to about 1000 nm, along thethickness direction of the display apparatus. The thickness may be atotal thickness and/or maximum thickness of such layer(s). When thethickness of each of the inorganic material layers 210 and 230 satisfiesthe above-described thickness range, the encapsulation layer 200A mayhave a relatively high sealing property to reduce or effectively preventcontamination (e.g., moisture, etc.) from reaching other elements of theencapsulation layer 200A. However, the material and thickness range ofthe inorganic material layers 210 and 230 are not limited thereto.

The organic material layer 220 of the encapsulation layer 200A mayinclude a photocurable organic material. The photocurable organicmaterial may include a photoresist (“PR”) material. The organic materiallayer 220 may include a titanium oxide (TiO₂) or the like as alight-scattering agent. The organic material layer 220 may planarize astep portion (not shown) formed due to a pixel defining layer of theOLED substrate 100A and/or may lessen stress caused by the inorganicmaterial layer 210 or 230. As a basic function, the organic materiallayer 220 includes the color control elements 20 a and 20 b and may thushave a color control function. The organic material layer 220 may have athickness of about 10 nm to about 10000 nm, for example, a thickness ofabout 1000 nm to about 10000 nm. The thickness may be a total thicknessand/or maximum thickness of such layer(s). Accordingly, the organicmaterial layer 220 may have a thickness greater than those of theinorganic material layers 210 and 230. When the thickness of the organicmaterial layer 220 satisfies the above-described thickness range, aplanarizing process may be effectively performed using the organicmaterial layer 220. However, the material and thickness range of theorganic material layer 220 are not limited thereto. When there are twoor more organic material layers 220, the thicknesses thereof may be thesame or different. In an embodiment of manufacturing the encapsulationlayer 200A, the organic material layer 220 may be easily formed using aprinting process, a photolithographic process, or the like.

In another embodiment, a cut-off filter type color filter may be usedinstead of one or more of the absorption type color filters 30 a, 30 band 30 c of FIG. 1 . Examples of the cut-off filter type color filtersare illustrated in FIG. 2 .

Referring to FIG. 2 , a color filter layer 310A may include cut-offfilter type first to third color filters 31 a, 31 b and 31 c. The firstcolor filter 31 a may filter out light of a blue wavelength region andlight of a green wavelength region among light incident thereto afterpassing through a first color control element 20 a. The second colorfilter 31 b may filter out light of a blue wavelength region and lightof a red wavelength region among light incident thereto after passingthrough a second color control element 20 b. The third color filter 31 cmay filter out light of a green wavelength region and light of a redwavelength region among light incident thereto after passing through alight-scattering element 21 c. The first color filter 31 a may bereferred to as a blue-and-green-cut filter (B,G cut filter). The secondcolor filter 31 b may be referred to as a blue-and-red-cut filter (B,Rcut filter). The third color filter 31 c may be referred to as agreen-and-red-cut filter (G,R cut filter). In other words, the firstcolor filter 31 a may be a first cut-off filter configured toselectively transmit light of a red wavelength region. The second colorfilter 31 b may be a second cut-off filter configured to selectivelytransmit light of a green wavelength region. The third color filter 31 cmay be a third cut-off filter configured to selectively transmit lightof a blue wavelength region. Color control/filtering characteristics ofthe display apparatus may be improved owing to the first to third colorfilters 31 a, 31 b and 31 c.

The cut-off filter type color filters 31 a, 31 b and 31 c may have, forexample, a distributed Bragg reflector (“DBR”) structure. The DBRstructure may be manufactured by repeatedly stacking two material layers(e.g., dielectrics) having different refractive indexes from each other.The DBR structure may be manufactured to transmit or reflect only lightof a desired wavelength band by controlling thicknesses of the materiallayers and a number of times of stacking the material layers, and isapplicable to the color filters 31 a, 31 b and/or 31 c. In anembodiment, for example, a SiO₂ layer and a TiO₂ layer may be repeatedlystacked to satisfy a condition of λ/4 (here, ‘λ’ represents a wavelengthof light), and a reflectance or transmittance of light of a desiredwavelength band may be increased by controlling the thicknesses of theselayers and a number of times of stacking the layers. The DBR structureis a well-known structure and is thus not described in detail here. Atleast one among the first to third color filters 31 a, 31 b and 31 c mayhave a structure different from the DBR structure, e.g., a relativelyhigh-contrast grating (“HCG”) structure. In FIG. 2 , components exceptthe color filter layer 310A may be the same or substantially the same asthose of FIG. 1 .

In another embodiment, the display apparatus may further include afourth sub-pixel region, as well as an R-sub-pixel (e.g., firstsub-pixel) region, a G-sub-pixel (e.g., second sub-pixel) region and aB-sub-pixel (e.g., third sub-pixel) region. The fourth sub-pixel regionmay be provided to exhibit a color (e.g., a fourth color) except forcolors of red (R), green (G) and blue (B). The color (e.g., the fourthcolor) may be, for example, white (W) but is not limited thereto. Casesin which the fourth sub-pixel region is further provided are illustratedin FIGS. 3 and 4 .

Referring to FIG. 3 , similar to FIG. 1 , an organic material layer 220a of an encapsulation layer 200B may include a first color controlelement 21 a, a second color control element 21 b, a firstlight-scattering element 22 c and a second light-scattering element 22d. A first inorganic material layer 210 a may be provided below theorganic material layer 220 a and a second inorganic material layer 230 amay be provided on the organic material layer 220 a. In this case, anOLED substrate 100B may be a white-OLED substrate which emits a whitecolor light.

A color filter layer 300B may include first to third color filters 32 a,32 b and 32 c, and a blank region corresponding to the secondlight-scattering element 22 d. The blank region may correspond to thefourth sub-pixel region described above, and white (W) color may begenerated from the blank region. An upper surface of the color filterlayer 300A at the first through third sub-pixel regions and an uppersurface of the encapsulation layer 200B at the fourth sub-pixel regiontogether may define a light emitting surface of the display apparatuswithout being limited thereto.

Referring to FIG. 4 , similar to FIG. 3 , a color filter layer 310B mayinclude cut-off filter type color filters 33 a, 33 b and 33 c. The colorfilter layer 310B may further include a blank region corresponding tothe fourth sub-pixel region described above.

In another embodiment, a color conversion element including a QD (a blueQD) may be used instead of the light-scattering element 21 c of FIG. 1 .An example of the color conversion element is illustrated in FIG. 5 .

Referring to FIG. 5 , an organic material layer 221 of an encapsulationlayer 201A may include a third color control element 20 c including a QDinstead of the light-scattering element 21 c of FIG. 1 . The QD of thethird color control element 20 c may be a blue QD. Thus, the third colorcontrol element 20 c may convert a color of light generated by an OLEDsubstrate 100A into blue light. In this case, the OLED substrate 100Amay be a light source generating light of color other than pure blue.The third color control element 20 c including the blue QD may be usedaccording to the type of the OLED substrate 100A. Although not shown, inthe present embodiment, a fourth sub-pixel region may be furtherprovided as shown in FIGS. 3 and 4 . Although not shown, in the presentembodiment, the cut-off filters 31 a, 31 b and 31 c may be provided asshown in FIG. 2 .

According to one or more embodiment of the present disclosure, a displayapparatus which has relatively high protective (encapsulation)properties with respect to an external environment and which isrelatively easy to manufacture may be provided. Furthermore, a displayapparatus capable of suppressing and/or minimizing color blurring orcolor mixing may be provided.

In manufacturing a conventional display apparatus, since an outgassingphenomenon may occur during a process for forming a QD color conversionlayer, in order to apply a QD color conversion layer to a top-emissionlight-emitting device, the QD color conversion layer may be directlyformed by patterning on an OLED device (e.g., at a display portionthereof) encapsulated with a multi-layer thin film or may be formed on aseparate glass substrate and thereafter bonded with an OLED device(e.g., at a display portion thereof). However, if the QD colorconversion layer is directly formed by patterning on the OLED device(e.g., at the display portion thereof) encapsulated with the multi-layerthin film, a photoluminescence (“PL”) property may be deteriorated whenthe QD color conversion layer is exposed to a general environment. Thus,the QD color conversion layer may be encapsulated by an additionalencapsulation process. In this case, the OLED device is primarilyencapsulated with a multi-layer thin film and is then secondarilyencapsulated. Thus, the encapsulation process is relatively complicated.Furthermore, since the distance between the OLED device and the QD colorconversion layer is relatively large, color implementationcharacteristics may be poor. If the QD color conversion layer is formedon the separate glass substrate and subsequently bonded with the OLEDdevice (e.g., at the display portion thereof), two substrates are usedand thus manufacturing costs may increase and a manufacturing processmay be complicated. Furthermore, the distance between the OLED deviceand the QD color conversion layer may increase and thus color mixing mayoccur.

However, according to one or more embodiment of the present disclosure,at least one organic material film, e.g., among the organic materiallayers 220, 220 a and 221, may be provided in the encapsulation layers200A, 200B and 201A encapsulating the OLED substrates 100A and 1006, andthe color control elements 20 a, 20 b, 20 c, 21 a and 21 b including QDsmay be disposed or formed in the organic material layers 220, 220 a and221. Accordingly, each of the OLED substrates 100A and 1006 and thecolor control elements 20 a, 20 b, 20 c, 21 a and 21 b may beencapsulated with one of the encapsulation layers 200A, 200B and 201A.Furthermore, since the distances between the OLED substrates 100A and100B and the color control elements 20 a, 20 b, 20 c, 21 a and 21 b arerelatively small, color blurring may be suppressed or minimized. Inaddition, the distances between the color control elements 20 a, 20 b,20 c, 21 a and 21 b and the color filter layers 300A, 300B, 310A and310B on the color control elements 20 a, 20 b, 20 c, 21 a and 21 b maybe maintained to a minimum. Thus, color mixing may be also suppressed orminimized. Accordingly, a display apparatus that has relatively highprotective (encapsulation) characteristics, is easy to manufacture, andis capable of suppressing and/or minimizing color blurring or colormixing may be provided.

A display apparatus according to an embodiment may further include athin-film transistor (“TFT”) array substrate having a plurality of TFTswhich drive pixel regions (or sub-pixel regions) of the OLED substrates100A and 1006. An example of the display apparatus is illustrated inFIG. 6 . FIG. 6 illustrates a case in which a TFT array substrate 10 isapplied to the display apparatus of FIG. 1 . However, it will beunderstood that the TFT array substrate 10 in FIG. 6 may be is appliedto any one of the display apparatus disclosed in FIGS. 1 to 5 .

Referring to FIG. 6 , a TFT array substrate 10 having a plurality ofTFTs (not shown) may be provided, and an OLED substrate 100A may beprovided on the TFT array substrate 10. The plurality of TFTs of the TFTarray substrate 10 may be devices configured to drive pixel regions (orsub-pixel regions) of the OLED substrate 100A. As such, the plurality ofTFTs of the TFT array substrate 10 may be connected to the OLEDsubstrate 100A and structures within the pixel regions (or sub-pixelregion) to drive the pixel regions (or sub-pixel regions) of the OLEDsubstrate 100A. The driving of the pixel regions (or sub-pixel regions)of the OLED substrate 100A may control the OLED substrate 100A togenerate and/or emit light to be incident on an encapsulation layer200A. The encapsulation layer 200A may be provided on the OLED substrate100A to receive light emitted therefrom, and a color filter layer 300Amay be provided on the encapsulation layer 200A to receive light emittedtherefrom.

FIG. 7 is a detailed cross-sectional view of a structure of a displayapparatus according to an embodiment.

Referring to FIG. 7 , a TFT array substrate 10 may be provided, and afirst electrode layer 110 having a plurality of first electrodes 110 a,110 b and 110 c may be provided on the TFT array substrate 10. Theplurality of first electrodes 110 a, 110 b and 110 c may be elementspatterned to respectively correspond to sub-pixel regions. The pluralityof first electrodes 110 a, 110 b and 110 c may be electrically connectedto TFT devices of the TFT array substrate 10. The plurality of firstelectrodes 110 a, 110 b and 110 c may include or be formed of atransparent electrode material such as an indium tin oxide (“ITO”).

An emission layer (EML) 130 including an organic material-based emissionmaterial may be provided on the first electrode layer 110. A holetransport layer (HTL) 120 may be provided between the EML 130 and thefirst electrode layer 110. An electron transport layer (ETL) 140 may beprovided on the EML 130. A second electrode layer 150 may be provided onthe ETL 140. Although not shown, a hole injection layer may be providedbetween the first electrode layer 110 and the HTL 120, and an electroninjection layer may be provided between the second electrode layer 150and the ETL 140. An intermediate material layer 160 may be furtherprovided on the second electrode layer 150. The intermediate materiallayer 160 may be transparent and may be formed of an insulatingmaterial.

Although the first electrode layer 110 is patterned and the secondelectrode layer 150 has a non-patterned shape in the present embodiment,the second electrode layer 150 may be patterned into a plurality ofelectrode elements according to circumstances. Alternatively, the firstelectrode layer 110 may not be patterned and the second electrode layer150 may be patterned, or both the first electrode layer 110 and thesecond electrode layer 150 may be patterned. Furthermore, the EML 130located between the first electrode layer 110 and the second electrodelayer 150 may be patterned into units corresponding to sub-pixels. Inthis case, all the HTL 120, the EML 130 and the ETL 140 may bepatterned. Although a case in which one emission unit having the HTL120, the EML 130 and the ETL 140 is used is illustrated and describedabove, a plurality of emission units may be used and a charge generationlayer may be applied between the plurality of emission units. In otherwords, an OLED device having a tandem structure may be used. Thecollection of the first electrode layer 110, the HTL 120, the EML 130,the ETL 140, the second electrode layer 150 and the intermediatematerial layer may form a light-emitting substrate which generates andemits light therefrom. In embodiments, the light-emitting substrateillustrated in FIG. 6 may be used as the OLED substrate in any one ofthe display apparatus disclosed in FIGS. 1 to 6 without being limitedthereto.

An encapsulation layer 200A and a color filter layer 300A according toan embodiment may be sequentially provided on the intermediate materiallayer 160. The first electrode layer 110 and the second electrode layer150 of an OLED substrate may be electrically separated (e.g.,disconnected) from an inorganic material layer 210 of the encapsulationlayer 200A. The encapsulation layer 200A and the color filter layer 300Aare as described above with reference to FIG. 1 and are thus notredundantly described again here.

Although FIG. 7 illustrates a case in which the TFT array substrate 10is located below the emission layer 130, the TFT array substrate 10 maybe located above the emission layer 130. In an embodiment, for example,the TFT array substrate 10 may be located between the EML 130 and theencapsulation layer 200A. In addition, components of the displayapparatus described above with reference to FIG. 7 may be variouslychanged.

FIG. 8 is a cross-sectional view of a structure of an encapsulationlayer applicable to a display apparatus according to another embodiment.

Referring to FIG. 8 , the encapsulation layer may include a firstinorganic material layer 215, a second inorganic material layer 235, anda first organic material layer 225 located between the first inorganicmaterial layer 215 and the second inorganic material layer 235. Thefirst inorganic material layer 215 and the second inorganic materiallayer 235 may be larger in planar size than the first organic materiallayer 225 and may be bonded to each other at outer side edges of thefirst organic material layer 225. That is, the first inorganic materiallayer 215 and the second inorganic material layer 235 extend furtherthan the side edges of the first organic material layer 225, to disposeends of the first inorganic material layer 215 and the second inorganicmaterial layer 235 spaced apart from the side edges of the first organicmaterial layer 225. Thus, side surfaces of the first organic materiallayer 225 may be covered with the inorganic material layer 235. In otherwords, the first organic material layer 225 may be completely sealed bythe first inorganic material layer 215 and the second inorganic materiallayer 235.

The first organic material layer 225 may be divided into a plurality ofsub-pixel regions, and include color conversion elements including QDs.When the first organic material layer 225 is completely sealed by theinorganic material layers 215 and 235 according to the presentembodiment, the protective (e.g., encapsulation) characteristic of thefirst organic material layer 225 may be more enhanced. That is,permeation of external oxygen or moisture may be reduced or effectivelyprevented due to the inorganic material layers 215 and 235 sealing thefirst organic material layer 225 therebetween.

FIG. 9 is a cross-sectional view of a display apparatus according toanother embodiment.

Referring to FIG. 9 , an encapsulation layer 200C may be provided on anOLED substrate 100. The encapsulation layer 200C may have a structure inwhich one or more inorganic material layers and one or more organicmaterial layers are alternately and repeatedly stacked, and a pluralityof color control elements may be included in at least one of the one ormore organic material layers. In an embodiment, for example, theencapsulation layer 200C may have a structure in which a first inorganicmaterial layer 210 b, a first organic material layer 220 b, a secondinorganic material layer 230 b, a second organic material layer 240 band a third inorganic material layer 250 b are sequentially stacked.

Color control elements 25 a and 25 b including QDs may be included in atleast one of the first organic material layer 220 b and the secondorganic material layer 240 b, e.g., in the first organic material layer220 b. A light-scattering element 26 c may be further included in thefirst organic material layer 220 b. Here, the encapsulation layer 200Chaving a five-layer structure is illustrated as an example but thenumber of material layers of the encapsulation layer 200C may vary.Alternatively, the color control elements 25 a and 25 b and thelight-scattering element 26 c may be included in the second organicmaterial layer 240 b rather than the first organic material layer 220 b.In embodiments, where more than one organic material layer is provided,the color control elements may be provided in only one organic materiallayer, without being limited thereto. In embodiments, where more thanone organic material layer is provided, the light-scattering element 26c may be provided in a same organic material layer as the color controlelements or in a different organic material layer from the color controlelements.

FIG. 10 is a cross-sectional view of a display apparatus according toanother embodiment. FIG. 10 is a modified example of the displayapparatus of FIG. 1 .

Referring to FIG. 10 , a cover layer 350 may be further provided on acolor filter layer 300A. An encapsulation layer 200A may protect andencapsulate an OLED substrate 100A and an organic material layer 220,whereas the cover layer may protect the color filter layer 300A. Anupper surface of the cover layer 350 may define a light emitting surfaceof the display apparatus without being limited thereto. The cover layer350 may include or be formed of an inorganic material and may be atransparent insulating layer. When the color filter layer 300A includesor is formed of an inorganic material, the cover layer 350 may beomitted. The cover layer 350 is applicable to not only the displayapparatus of FIG. 1 but also the display apparatuses of FIGS. 2 to 7 .

FIG. 11 is a graph showing an electroluminescence (“EL”) spectrum of ablue-OLED substrate applicable to a display apparatus according to anembodiment. The EL spectrum is illustrated with an intensity inarbitrary units (a.u.) with respect to wavelength in nanometers (nm) forblue light.

Referring to FIG. 11 , blue light is generated from the blue-OLEDsubstrate. However, an OLED substrate applicable to a display apparatusaccording to an embodiment is not limited to the blue-OLED substrate,and may be various other colored OLED substrates such as a white-OLEDsubstrate, a cyan-OLED substrate, or the like.

FIG. 12 is a graph showing a photoluminescence (“PL”) quantum yield(“QY”) in percent (%) according to wavelengths in nanometers (nm) of acolor conversion element including a red-QD and a color conversionelement including a green-QD applicable to a display apparatus accordingto an embodiment.

Referring to FIG. 12 , the color conversion element including thegreen-QD has a PL quantum yield up to approximately a green wavelengthregion, and the color conversion element including the red-QD has a PLquantum yield approximately until a red wavelength region. The colorconversion element including the red-QD and color conversion elementincluding the green-QD may be respectively applied to the first colorcontrol element 20 a and the second color control element 20 b of FIG. 1.

FIG. 13 is a graph showing a variation in transmittance in percent (%)versus wavelengths in nanometers (nm) of a color conversion elementincluding a red-QD and a color conversion element including a green-QDapplicable to a display apparatus according to an embodiment.

Referring to FIG. 13 , the color conversion element including thegreen-QD has a relatively high transmittance starting from approximatelya wavelength corresponding to a green wavelength region, and the colorconversion element including the red-QD has a relatively hightransmittance starting from approximately a wavelength corresponding toa red wavelength region.

FIG. 14 is a graph showing a variation in a transmittance in percent (%)versus a wavelength in nanometers (nm) of an absorption type colorfilter applicable to a display apparatus according to an embodiment. Thegraph of FIG. 14 shows a variation in a transmittance (%) versus awavelength (nm) of each of an absorption type red-color filter, anabsorption type green-color filter and an absorption type Blue-colorfilter. The absorption type red-color filter, the absorption typegreen-color filter and the absorption type blue-color filter may berespectively applied to, for example, the first color filter 30 a, thesecond color filter 30 b, and the third color filter 30 c of FIG. 1 .

FIG. 15 is a graph showing a variation in a transmittance in percent (%)versus a wavelength in nanometers (nm) of a cut-off type color filterapplicable to a display apparatus according to an embodiment. The graphof FIG. 15 shows a variation in a transmittance (%) versus a wavelength(nm) of each of a cut-off type red-color filter, a cut-off typegreen-color filter and a cut-off type blue-color filter. The cut-offtype red-color filter, the cut-off type green-color filter and thecut-off type blue-color filter may be respectively applied to, forexample, the first color filter 31 a, the second color filter 31 b andthe third color filter 31 c of FIG. 2 .

FIG. 16 is a graph showing a spectral radiance difference between when alight-scattering agent is applied to blue light and when thelight-scattering agent is not applied to the blue light. The spectraldifference is expressed in watt per steradian per square metre pernanometre (W/(m²·sr·nm)).

Referring to FIG. 16 , when the light-scattering agent was not applied(“Before light-scattering agent”), light was not appropriately dispersedand thus a plurality of peaks occurred. When the light-scattering agentwas applied (“After light-scattering agent”), light was appropriatelydispersed and thus one relatively smoothly curved one peak occurred.

FIG. 17 is a graph showing an emission spectrum according to awavelength of a display apparatus according to an embodiment. Theemission spectrum is expressed in watt per steradian per square metre(W·sr⁻¹·m⁻²).

Referring to FIG. 17 , a spectrum (“Red-AF-CF”) of light generated froman OLED substrate (as a light source) after the light passed through acolor conversion element including a red-QD corresponds to a red lightregion, a spectrum (“Green-AF-CF”) of the light after the light passedthrough a color conversion element including a green-QD corresponds to agreen light region, and a spectrum (“Blue”) of light which has passedthrough a non-color-converting region of an organic material layer suchas in a blue pixel region corresponds to a blue light region.

The display apparatuses according to one or more embodiment describedabove are applicable to various types of electronic devices. Forexample, the display apparatuses are applicable to relativelysmall-sized electronic devices such as portable devices or wearabledevices, and medium and relatively large-sized electronic devices suchas household appliances.

Although many matters have been described above in detail, it should beunderstood that they are not intended to restrict the scope of thepresent disclosure and are provided to give examples. For example, itwould be apparent to those of ordinary skill in the art that variouschanges may be made in the structures of and relations among the OLEDsubstrates, the encapsulation layers, the QD color control elements, thecolor filter layers and the display apparatuses described above withreference to FIGS. 1 to 10 . In an embodiment, for example, abottom-emission light-emitting device may be used as an OLED substrateinstead of a top-emission light-emitting device shown in the figures,and various changes may be made in structures of a QD color controlelement and/or a color filter layer according to color of light emittedfrom the OLED substrate. Furthermore, structures according toembodiments or parts thereof are applicable to display apparatuses andother types of devices, e.g., lighting devices. Accordingly, the scopeof the present disclosure should be determined not by the embodimentsset forth herein but by the technical idea defined in the appendedclaims.

What is claimed is:
 1. A display apparatus comprising: a plurality ofsub-pixel regions at which color light is emitted to display an image,the plurality of sub-pixel regions including a first sub-pixel region, asecond sub-pixel region, and a third sub-pixel region; an organiclight-emitting device substrate which generates and emits a light, theorganic light-emitting device substrate comprising a cyan organiclight-emitting device substrate which emits cyan light; and in orderfrom the organic light-emitting device substrate: a first inorganicmaterial layer; an organic material layer comprising: a first colorcontrol element which corresponds to the first sub-pixel region,includes a first quantum dot converting a color of the emitted lightfrom the organic light-emitting device substrate to a first color andemits light of the first color; a second color control element whichcorresponds to the second sub-pixel region, includes a second quantumdot converting the color of the emitted light from the organiclight-emitting device substrate to a second color and emits light of thesecond color; and a third color control element which corresponds to thethird sub-pixel region, and includes a third quantum dot converting thecolor of the emitted light from the organic light-emitting devicesubstrate to a third color, or a light-scattering element maintainingthe color of the emitted light from the organic light-emitting devicesubstrate; a second inorganic material layer; and a color filter layercomprising: a first color filter corresponding to the first colorcontrol element, a second color filter corresponding to the second colorcontrol element, and a third color filter corresponding to the thirdcolor control element or the light-scattering element.
 2. The displayapparatus of claim 1, wherein each of the first quantum dot, the secondquantum dot, and if the third quantum dot is present, the third quantumdot independently comprises a material selected from the groupconsisting of a Group II-VI-based semiconductor, a Group III-V-basedsemiconductor, a Group IV-VI-based semiconductor, and a Group IV-basedsemiconductor.
 3. The display apparatus of claim 1, wherein each of thefirst quantum dot, the second quantum dot, and if the third quantum dotis present, the third quantum dot independently comprises a monolithicstructure or a core-shell structure.
 4. The display apparatus of claim1, wherein the first color is red, the second color is green and thethird color is blue.
 5. The display apparatus of claim 1, wherein thefirst color filter is a first cut-off filter which selectively transmitslight in a red light wavelength region or an absorption-type red colorfilter, the second color filter is a second cut-off filter whichselectively transmits light in a green light wavelength region or anabsorption-type green color filter, and the third color filter is athird cut-off filter which selectively transmits light in a blue lightwavelength region or an absorption-type blue color filter.
 6. Thedisplay apparatus of claim 1, wherein the organic material layer furthercomprises: a photocurable organic material; and a light-scatteringagent.
 7. The display apparatus of claim 1, wherein the organic materiallayer has a thickness of about 10 nanometers to about 10,000 nanometers.8. The display apparatus of claim 1, wherein each of the first inorganicmaterial layer and the second inorganic material layer independentlycomprises a material selected from the group consisting of a metalnitride, a metal oxide, a metal oxynitride, a metal carbide, and acombination thereof.
 9. The display apparatus of claim 1, wherein eachof the first inorganic material layer and the second inorganic materiallayer independently has a thickness of about 10 nanometers to about5,000 nanometers.
 10. The display apparatus of claim 1, wherein each ofthe first inorganic material layer and the second inorganic materiallayer independently comprises an insulating layer or a semiconductorlayer; or has an encapsulation property.
 11. The display apparatus ofclaim 1, further comprising a fourth sub-pixel region, producing a colorother than colors of the first to third sub-pixel regions, wherein theorganic material layer further comprises a light-scattering element,corresponding to the fourth sub-pixel region.
 12. The display apparatusof claim 1, wherein the second inorganic material layer is furtherprovided directly on the third color control element without anotherintervening layer.